What Causes von Willebrand Disease?
Von Willebrand disease (VWD) is an inherited bleeding disorder caused by a defect or deficiency of von Willebrand factor (VWF). VWF is a protein in your blood that is necessary for normal blood clotting. It is produced by the cells that line the blood vessel walls and acts like glue, sticking to blood cells called platelets. Together, VWF and platelets form a plug to prevent the blood from leaking out of the site of blood vessel injury. People with inherited (congenital) VWD are unable to make this plug because they either do not have enough VWF or their VWF doesn’t work properly.1
Because VWD is nearly always inherited from one or both parents, the disorder runs in families.1 Because symptoms can be very mild in some people, a family member could have VWD and not know it. Here are the types of VWD and how they are inherited:
- VWD type 1, type 2A, type 2B, and some cases of type 2M are passed from parent to child in a pattern called autosomal dominant inheritance.2 This means that a child inherits 1 mutated gene for the disorder from 1 parent.3
- VWD type 2N, type 3, and some cases of type 2M are passed from parent to child in a pattern called autosomal recessive inheritance.2 This means that a child inherits 2 mutated genes, one from each parent.3
Because of these inheritance patterns, a family history of the bleeding disorder is the primary risk factor for VWD, though in rare cases VWD can develop later in life from other medical conditions. There is no particular race or ethnicity in which VWD is more common than others.
- What is von Willebrand disease? National Institutes of Health; National Heart, Lung, and Blood Institute website. http://www.nhlbi.nih.gov/health/health-topics/topics/vwd. Accessed October 21, 2014.
- Scientific overview. In: The Diagnosis, Evaluation and Management of von Willebrand Disease. Washington, DC: National Institutes of Health; National Heart, Lung, and Blood Institute; 2007. NIH Publication No. 08-5832. https://www.nhlbi.nih.gov/health-pro/guidelines/current/von-willebrand-guidelines/full-report/2-scientific-overview.htm. Accessed October 21, 2014.
- What are the different ways in which a genetic condition can be inherited? Genetics Home Reference website. http://ghr.nlm.nih.gov/handbook/inheritance/inheritancepatterns. Accessed October 22, 2014.